SQL 查询 VS LinQ

          select v.Branch, v.Store, v.ChildId,SUM(r.Cash) from OrderDetail as r
          inner join Order as v on r.OrderId equals v.Id
          where r.OrderId == 123
          group by v.Branch, v.Store, v.ChildId

LinQ

          var list = (from r in ctx.OrderDetail
                        join v in ctx.Order on r.OrderId equals v.Id
                        where r.OrderId == 123
                        group new { v, r } by new { v.Branch, v.Store, v.ChildId } into g
                        select new
                        {
                            Branch = g.Key.Branch,
                            Store = g.Key.Store,
                            ChildId = g.Key.ChildId,
                            TotalCash = g.Sum(p => p.r.Cash)
                        }